Cork native Ron Clifford found himself in the World Trade Center lobby by coincidence on September 11, 2001. What he didn’t know as chaos and fire erupted around him that morning was that his sister Ruth Clifford McCourt, 45, and her child Juliana, only four, were on the plane that hit the South Tower.

Now, nearly 11 years since losing them, Clifford will face the men who masterminded the attacks that killed his relatives and 2,975 other confirmed victims.

“We need to prove these people are culpable. They planned this, orchestrated it, carried it out to a tee,” Clifford told the Irish Voice in an exclusive interview.

“They’ve had an incredibly negative effect on humanity as we know it.

“I miss my sister and my niece every day. I wonder on their birthdays what they would be like at this age.”

The next hearings are scheduled for August 22-24 and 26-28 in Guantanamo Bay, Cuba, according to court documents. Clifford couldn’t say when he expects to appear in court beyond “probably toward the middle of the trial.”

Clifford said he usually avoids bringing back memories of September 11. He can’t bring himself to visit the memorial at Ground Zero, although he says it’s a “wonderful tribute.” As a victim family member, Clifford has clearance to view the military trial proceedings via CCTV, but has no intention of doing so.

“Why put yourself in that upsetting situation?” he asked.

“I would just want to walk into court, say my piece, and know that he [Khalid Sheikh Mohammed] was judged and sentenced accordingly,” Clifford said. “I don’t think emotionally I could go through it every day and watch it. I think I’d just get very angry.”

But Clifford is willing to relive the day the towers fell one more time for the sake of justice. He also testified at the 2006 trial of Zacarias Moussaoui, who was sentenced to life in prison without parole for his involvement in the September 11 attacks and other terrorist plots.

Testifying “brings you right there again, it brings you right to all the stuff we’ve had to endure,” Clifford said. “It brings you to all the stuff we’ve been trying to live and forget.”

Clifford’s testimony in 2006 helped him and his family better come to terms with the tragedy, he said. His daughter, who was 15 at the time—and had turned 11 on September 11, 2001—accompanied him and sat across from Moussaoui as, for the first time, she heard her father’s story.

“A cloud left our family,” Clifford said. “It was not the unspeakable thing any more. We were able to discuss aspects of the trial and the law, and what happened to me that day.”

Though testifying could make Clifford a target for violence, he said he chooses not to worry about the risks.

“I’ve often wondered, will someone come up and shoot me as a result?” he said. “I don’t think I could live in that kind of paranoia.”

When profiled in Irish Voice founding publisher Niall O’Dowd’s 2002 book "Fire in the Morning," Clifford expressed Christian mercy toward the plot’s masterminds. But time has now hardened his views.

“My attitude has changed,” he told the Irish Voice. “I do believe in forgiveness, but they don’t want to be forgiven. They want to be martyred.

“They’re getting more and more radical by the day,” he said. “For me it comes down to murdering people in cold blood.”

The interrogation techniques used on the Khalid Sheikh Mohammed and the other defendants, techniques labeled in some venues as torture, were necessary, according to Clifford.

“Without the use of force and torture, the U.S. would have been unable to avert other catastrophic events and find out who was behind these events,” he said. “I think that was the only course in extracting this information.”

The Khalid Sheikh Mohammed trial, for Clifford, is a necessary element to justice, but one that he’s looking forward to having behind him.

“The big thing is my belief in the American system of justice, at any level, whether it’s federal or military, it’s a very good, fair system,” Clifford said. “I’m confident they will get a fair trial, as Moussaoui did. He got a fair trial and we watched it.”

Clifford was against the short-lived push to move the trial from Guantanamo Bay to New York City because some necessary evidence wouldn’t have been constitutionally admissible in a criminal court, he said. Regardless of the venue, he said the trial will be cathartic for both victims and the nation as a whole.